新增阅读器功能，待优化

lib/service/book_server.dart

@@ -0,0 +1,98 @@
+import 'dart:io';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+import 'package:shelf/shelf.dart' as shelf;
+import 'package:shelf/shelf_io.dart' as io;
+
+/// 本地 HTTP 服务器，为 WebView 提供书籍文件和 foliate-js 资源
+class Server {
+  static final Server _singleton = Server._internal();
+  factory Server() => _singleton;
+  Server._internal();
+
+  HttpServer? _server;
+  bool get isRunning => _server != null;
+  int get port => _server?.port ?? 0;
+
+  Future<void> start({int preferredPort = 0}) async {
+    if (_server != null) {
+      await stop();
+    }
+
+    final handler = const shelf.Pipeline()
+        .addMiddleware(shelf.logRequests())
+        .addHandler(_handleRequest);
+
+    try {
+      _server = await io.serve(handler, '127.0.0.1', preferredPort);
+    } catch (_) {
+      _server = await io.serve(handler, '127.0.0.1', 0);
+    }
+  }
+
+  Future<void> stop() async {
+    if (_server == null) return;
+    await _server!.close(force: true);
+    _server = null;
+  }
+
+  Future<shelf.Response> _handleRequest(shelf.Request request) async {
+    final uriPath = request.requestedUri.path;
+
+    // 书籍文件请求
+    if (uriPath.startsWith('/book/')) {
+      final bookPath = Uri.decodeComponent(uriPath.substring(6));
+      final file = File(bookPath);
+      if (!await file.exists()) {
+        return shelf.Response.notFound('Book not found');
+      }
+      return shelf.Response.ok(
+        file.openRead(),
+        headers: {
+          'Content-Type': 'application/epub+zip',
+          'Access-Control-Allow-Origin': '*',
+        },
+      );
+    }
+
+    // foliate-js 资源请求
+    if (uriPath.startsWith('/foliate-js/')) {
+      final assetPath = 'assets/foliate-js/${uriPath.substring(12)}';
+
+      String contentType;
+      if (uriPath.endsWith('.html')) {
+        contentType = 'text/html';
+      } else if (uriPath.endsWith('.css')) {
+        contentType = 'text/css';
+      } else if (uriPath.endsWith('.js') || uriPath.endsWith('.mjs')) {
+        contentType = 'application/javascript';
+      } else if (uriPath.endsWith('.json')) {
+        contentType = 'application/json';
+      } else if (uriPath.endsWith('.svg')) {
+        contentType = 'image/svg+xml';
+      } else {
+        contentType = 'application/octet-stream';
+      }
+
+      try {
+        // 优先尝试 load() 加载为字节流（最可靠），再转为字符串或直接返回
+        final data = await rootBundle.load(assetPath);
+        return shelf.Response.ok(
+          data.buffer.asUint8List(),
+          headers: {
+            'Content-Type': contentType,
+            'Access-Control-Allow-Origin': '*',
+          },
+        );
+      } catch (e) {
+        debugPrint('[Server] Asset not found: $assetPath error=$e');
+        return shelf.Response.notFound('Asset not found: $assetPath');
+      }
+    }
+
+    return shelf.Response.ok(
+      'OK',
+      headers: {'Access-Control-Allow-Origin': '*'},
+    );
+  }
+}